The present invention relates to a cooling and heating system for a machine, such as a wheeled loader or dumper.
Machines such as wheeled loaders and dumpers comprise a number of components which are controlled by hydraulics. For example, hydraulic cylinders are used in order to operate a working implement, such as a scoop, which is arranged on a loading arm assembly of a wheeled loader.
When the machine is cold-started, it is desirable to increase the temperature of the hydraulic liquid in the hydraulic system of the machine rapidly so as to reduce friction and wear in hydraulic cylinders and other hydraulic components. Reduced friction results in the fuel consumption of the vehicle being lower. When the temperature increases, the quantity of water given off from the hydraulic liquid also increases, which is desirable.
When the hydraulic liquid has been heated up and the hydraulic components of the machine are used, heat is generated as a result of the increase in pressure in the hydraulic liquid. The hydraulic liquid must then be cooled so that the hydraulics system is not damaged by the temperature of the hydraulic liquid being too high.
In order to reduce friction losses and thus reduce the fuel consumption of the machine, it is also desirable that the transmission oil in the gearbox of the machine and the lubrication oil in the wheel axles of the machine are heated up rapidly when the machine is cold-started.
In the same way as for the hydraulics system, it is necessary to cool the transmission oil and lubrication oil when the machine is used in order that the gearbox and the wheel axles are not damaged.
It is previously known to heat up the hydraulic liquid of a machine by means of the cooling water from an internal combustion engine in the machine. The disadvantage of heating the hydraulic liquid using the cooling water of the internal combustion engine is that it takes too long to heat up the hydraulic liquid, which results in high fuel consumption when the machine is cold-started.
The object of the present invention is to bring about rapid heating up of the hydraulic liquid of a machine in order to reduce the fuel consumption of the machine when cold-started.
Another object of the present invention is to achieve rapid heating up of the lubrication oil for at least one wheel axle of the machine.
A further object of the present invention is to achieve rapid heating up of the transmission oil for a gearbox of the machine.
A further object of the invention is to achieve cooling of the hydraulic liquid, the lubrication oil and the transmission oil during operation of the vehicle.
Such a cooling and heating system provides rapid heating up of the hydraulic liquid, the lubrication oil and the transmission oil, which reduces the fuel consumption of the machine, and also reduces wear on the hydraulics system, the wheel axles and the gearbox of the machine. The cooling and heating system also provides controlled cooling of the hydraulic liquid, the lubrication oil and the transmission oil when the machine is used.